In recent times, emergency warning devices or flares have been designed to be carried im motor vehicles and used on the roadway to warn approaching traffic of the presence of a stopped vehicle. Such devices are intended to reduce deaths and injuries due to rear end collisions between moving traffic and disabled vehicles. Governmental regulations have been established to standardize the requirements for such devices in terms of size, configuration, color, reflectivity, luminance, stability and durability. Typical standards are the Motor Vehicle Safety Standard No. 125 in the United States and Canadian Standards Association standard D171 in Canada. These standards provide that the emergency warning device be triangular in shape and have red reflective material and orange fluorescent material on the opposed faces of the triangle. The standards further call for the warning device as having stability such that when the warning device is erected on a horizontal brush concrete surface, both with and against the brush marks and subjected to a horizontal wind of 40 m.p.h. in any direction for three minutes (a) no part of it shall slide more than three inches from its initial position; (b) its triangular portion shall not tilt to a position that is more than ten degrees from the vertical; and (c) its triangular position shall not turn through a horizontal angle of more than ten degrees in either direction from the initial position.
It has been shown in studies made by the present inventors and confirmed by The National Aeronautical Establishment, Ottawa, Canada, that the present standards on stability are inadequate to withstand the normal winds or the effect of a passing vehicle on the warning devices. Accordingly the National Aeronautical Establishment has recently recommended that the weight of the device thus be substantially increased.
The problem with such a solution is that it would require an increase in the weight of present emergency road warning flares to about 250% or more of the present weight. Such a requirement would thus increase the weight that must be carried by the vehicle since each vehicle is presently required to carry three warning devices making it difficult and awkward to handle them, to attach them to the vehicle for storage and increasing fuel consumption of the vehicle.
The present invention is to provide an improved emergency warning device which does not materially increase the weight to be carried by the vehicle; which effectively will withstand crosswinds and winds due to passing vehicles substantially above the present standards; and which preferably can be folded and stored in a volumetric area as emergency warning devices presently are stored.
In accordance with the invention, vane means are provided on the emergency warning device and is shaped and positioned such that air flow against a face of the triangle produces a downward force tending to prevent movement of the device relative to a road surface.